Ominous

Adjective

1. Threatening, menacing

2. Of or being an omen, especially an evil one

Example: A shark

Synonym: Horrible

Antonym: Safe

Consolidate

Verb

1. To form into a compacted mass

2. To unite into one system or body

Example: trash compactor

Synonym: Mold
Antonym: Tear

Siege

Adjective

1. Encirclement or blockade of a town or fortress

2. A proglonged period as of illness or distress

Example: Take

Synonym: Capture

Antonym: Give

Emerge

Verb

1. To come up or rise from

2. To become obvious or evident

Example: A bomb

Synonym: Appear

Antonym: Sink

Momentarily

Abverb

1. For only a moment

2. Very soon

Example: Blinking

Synonym: Abruptly

Antonym: Prolonged